George Zimmerman's statement to police about what 17-year-old Trayvon Martin was up to on Feb. 26 in Sanford, Fla., "is completely contradicted" by the boy's cellphone records, an attorney for Martin's family just said during a news conference in Fort Lauderdale, Fla.

Attorney Benjamin Crump said the African-American teenager had been talking to friends all day and, as first reported earlier today by ABC News, was on the phone with a young girl when he was confronted by, in Crump's words, "neighborhood association loose cannon" Zimmerman.

The girl, Crump said, says Martin was just trying to get back to the house he and his father had been visiting when Zimmerman came into the picture. She heard Martin ask "why are you following me?" Crump said. Another voice, according to the girl, asked at least twice "what are you doing around here?"

Moments later, Martin was shot in the chest.

The 28-year-old Zimmerman, who had called police to report seeing a "suspicious" person and was advised not to follow that person, has told police he acted in self defense.

As we've been reporting, Martin's death has reignited a national conversation about race and racial profiling. And it has led to charges from Martin's family and their supporters that local police failed to adequately investigate. "Arrest killer. He killed this child in cold blood," Crump said a moment ago.